Use a screw that prevents galvanic corrosion

If metals with different electric potentials come in contact with water, a battery structure is formed and electrons are exchanged between the dissimilar metals, causing corrosion of the metal with lower natural electric potential. Screws that prevent this corrosion due to differences in natural electric potential (dissimilar metal contact corrosion (galvanic corrosion)) are available. The effective period of galvanic corrosion prevention is about 5 times longer than hot dip zinc plating so it suitable for fixing aluminum parts and materials that are used outdoors.

For the bases of outdoor equipment installed outdoors

Recommended product

Galvanic Corrosion Prevention Treated Bolts  SNH-GJ